Underlap forming means for wrapping machines



Nov. 3o, 1965 F. B. ROBERTS 3,220,160

UNDERLAP FORMING MEANS FOR WRAPPING MACHINES Filed May 16, 1962 5 Sheets-Sheet 1 5 Sheets-Sheet 2 F. B. ROBERTS UNDERLAP FORMING MEANS FOR WRAPPING MACHINES Nov.

Filed May 16, 1962 Nov. 30, 1965 F. B. ROBERTS 3,220,160

UNDERLAP FORMING MEANS FOR WRAPPING MACHINES Filed May 16; 1962 5 Sheets-Sheet 5 Nov. 30, 1955 F. B. ROBERTS 3,220,160

UNDERLAP FORMING MEANS FOR WRAPPING MACHINES Filed May 16, 1962 5 Sheets-Sheet 4 Nov. 30, 1965 F. B. ROBERTS 3,220,160

UNDERLAP FORMING MEANS FOR WRAPPING MACHINES Filed May 16, 1962 5 sheets-sheet s :ELEL

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BY fw f7/Ml Manny/5 United States Patent 3,220,160 UNDERLAP FORMENG MEANS FR WRAPIING MACIHNES Franklin B. Roberts, Springfield, Mass., assigner to Package Machinery Company, East Longmeadow, Mass., a corporation of Massachusetts Filed May 16, 1962, Ser. No. 195,079 8 Claims. (Cl. 53--233) The present invention relates to improvements in forming the underlap of a wrapper for an article.

The present invention is best understood as an improvement in the type of wrapping machines disclosed in U.S. Patent No. 2,810,246.

In that patent articles are continuously advanced as a wrapper is draped about an article and then the leading and trailing end portions thereof are folded against the bottom face of the article in lapped relationship to encircle the article within the wrapper. The means provided for so folding the wrapper end portions advantageously have the capability of disposing the trailing end directly against the bottom face of the article and then laying the leading wrapper end over the trailing wrapper end in lapped relationship.

The object of the invention is to attain higher rates of operation as they are encircled in a wrapper and also to give greater support to the articles as this is done so as to minimize, if not totally eliminate, the problems which result from articles being inadvertently displaced during the wrapping operation.

A further object of the invention is to attain the above ends in a simple, effective and economical manner.

The above ends are attained, in its barest essentials, by a first folder unit and a second folder unit. Means are provided for moving said folder units at different rates around closed paths. These paths have coextensive working portions wherein the wrapper is folded against the bottom of the article. Other remote portions of these paths are divergent to permit one folder unit to pass the other and thereby avoid a collision between the folder units which are traveling at different rates.

The above and other related objects and features of the invention will be apparent from a reading of the following description of the disclosure found in the accompanying drawings and the novelty thereof pointed out in the appended claims.

In the drawings:

FIG. l is an elevation, in longitudinal section, of underlap forming means embodying the present invention;

FIG. 2 is an enlarged view of a portion of FIG. l;

FIG. 3 is a plan view, with portions cut away and in section of the elements seen in FIG. 2;

FIG. 4 is a section taken on line IV-IV in FIG. 3;

FIG. 5 is a section taken on line V-V in FIG. 3;

FIGS. 6 and 7 are sections, on an enlarged scale, taken generally on line VI-VI and showing diiferent positions of one of the folder units.

Having reference lirst to FIG. 1, articles a are advanced over a first platform 10 by an overhead conveyor 12 comprising flights 14 which grip opposite end faces of the article. A wrapper w is draped around each article a. The leading end portion x thereof lies against the bottom of the article and the trailing end portion y trails therebehind as the articles are advanced over plate 10. The means for so draping the articles and introducing them between the ights 14, and the means for mounting and driving the conveyor 12, may take the same form as disclosed in the patent above referred to and reference is made thereto for the constructional details of such means.

The articles a are transferred from the platform 10 to lap forming means comprising a series of first folding units 16 and a series of second folding units 18.

Ffice Each folding unit 16 comprises a suction bar 20, FIGS. 3 and 6, which is mounted on an angle plate 22 which in turn is secured to a leaf 24 of a piano hinge 25. The central portions of the leaf 24 (FIG. 4) and the depending section of angle plate 22 are cut away to provide clearance for parts later described. The other leaf 26, of the piano hinge 25 (FIGS. 1 and 6) lies in the same plane as the suction bar 20 and platform 10 and is secured tod a bar 28. The opposite ends of the bar 28 (FIG. 4) are secured to a pair of matched chains 30. The folding unit 16 may also comprise a bar 32 (FIGS. 3 and 5) which is secured at its opposite ends to the chains 30 with its central portion disposed below the level of the bars 20 and 28. Springs 34 (FIG. 6) extends from spring pins 36 on opposite ends of the bar 32 and are hooked into openings in the plate 22 and hinge leaf 24. The spring 34 thus urges the suction bar 20 to pivot away from the article a. This pivotal movement is controlled by fixed cam plates 37 (FIGS. 3, 4 and 6) at opposite ends of the bar 20. Bearing brackets 38 are secured to the undersurface of the plate 22 at opposite ends of the suction bar 20. A cam follower 40 is mounted on each of the blocks 38 and engages the fixed cam plates 37.

The chains 30 are trained about a pair of sprockets 44 (FIGS. 1 and 3) and a pair of sprockets 46. The sprockets 44 are secured to a shaft 48 which is driven from a power source through sprocket 49 (FIG. 3) and in proper timed relationship to the movement of the overhead conveyor 12 which controls the advance of the articles a, as will later be more fully apparent. The sprockets 46 rotate freely about the axis of the shaft 50 on which they are mounted.

Each suction bar 20 (-FIGS. 2, 3 rand 4) comprises an elongated plenum ychamber 52 and has a `series of holes 54 communicating therewith and opening on the upper surface of the bar 20. An elbow tube 5S is secured to the bar 20 and communicates with the plenum chamber 52. A vacuum hose 56 is connected to the tulbe 55 and extends through a support 58 mounted on the undersurface of the bar 32 and then is connected to a second elbow tube 60 which depends from -a block 62 mounted on the undersurface of the bar 28 of the preceding folder unit 16. The tube 60 projects into a passageway 64 having an opening 66 on the undersurface of block 62. As the bar 28 of the preceding folder unit 16 turns `around the shaft 48, the opening 64 of passageway 66 is brought into registration with a tubular projection 68 having a cup 70 which sealingly engages the block 62. The projection 68 communicates with a suction passageway within a hub 72, on shaft 48, which is connected to Ian appropriate vacuum source through a pipe 74. The constructional details of the suction chamber within hub 72 are fully explained in U.S. Patent No. 2,952,957.

Each of the second folding units 18 comprises a bar 76 (FIGS. 2, 3 and 5) which is secured at its opposite ends to a pair of chains 78. The chains 78 are trained around sprockets 80 secured to the shaft 48 around idler sprockets 82 and around sprockets 84 mounted on the shaft 50. The chains 80 are driven by the -sprockets 80 which, being of a greater diameter than the sprockets 44, cause the chains 78 to move at a faster linear rate than the chains 30. It will also be noted that the central portion of the bars 76 is offset to lie in the same plane as the platform 10 as the bars 76 are carried along the chains 78. T-hus the paths of travel of the folding units 16 and 18 -are coextensive as they are carried along the upper parallel runs of the chains 30 and 78 through what can be termed `the working portions of their paths of travel. The folding units l16 are so spaced that each unit 16 is disposed beneath and supports one of the articles a along the upper run of chains 30. The folder units 16 move at the same rate as the articles a so that this registered relation is maintained. The suction bar 2t) is disposed beneath and adjacent the end of the lead- `ing end portion x of the wrapper w. Viewing the unit 16 immediately above the sprocket 50 in FIG. 1, it will be seen that the folding unit 18 associated therewith is spaced a substantial distance therefrom. In fact, it overlies the 'bar 32 of t-he preceding unit y16, clearance for such overlying relation being shown in FIG. 5. As the folder unit 16 advances the `article to the next illustrated position, the ltrailing end portion y of the wrapper w fall-s between the two units 16 and 18. lIf necessary, fluid pressure assist means can be provided to aid in so disposing the end portion x, as is known in the art. The bar 76 traveling at a faster rate than the unit 16 overtakes the article a and, as shown in relation to the third article a, begins to fold the end portion y against the bottom of the article. As this occurs, the cam track 42 drops away yallowing the suction bar 20 to pivot away from the tbottom of the article aand carrying with it the wrapper end portion x. Further movement of the folding units 16 and 18 causes the wrapper end y to be more fully laid against the bottom face of the article a as the article is advanced onto a second platform 88. As this occurs, the end portion x is laid against the bottom of the article and lapped over the end portion y. The underlap of the article is then complete and the articles may be advanced by known means for folding the lateral extensions of the wrapper or otherwise completing the wrapping operation.

At this point it will be noted that camming blocks 90 are secured to the bars 76 in alignment with the rolls 40. In the event any 'bar 20 fails to pivot about its hinge 25 at the proper time, the blocks 90 will engage land displace the rolls 40 to prevent a collision between the folder units 16 and 18.

As the `folder units 16 and 1S turn around the shaft `418, they move at the same angular velocity so that there is no relative movement therebetween. As the chains '78 pass from the sprockets 86 to the sprockets 82, they diverge from the chains 30, following a path which permits the folder units 1S -to pass over the folder units 16. This leap-frogging of the units 18 takes place along the bottom runs of the chains 30 and 78. Thus, it is that the units 18 are brought into cooperative relation with successive folding units 16.

Various modifications of the structural arrangement herein disclosed will occur to those skilled in the art within the scope of lthe inventive concepts which are defined by the appended claims.

Having thus disclosed the invention, what is claimed as novel and desired to be secured by Letters Patent of the United States is:

1. In a wrappingmachine, first and second folder units, a platform, said folder units being movable around closed paths, said paths having coextensive working portions extending towards said platform, said paths then falling beneath said platform to a point of divergence, the path of said second unit from said point Iof divergence back to said work portions being greater than the length of the Apath of said iirst unit between these points, said rst unit being spaced la substantial distance from said second folder unit at the beginning of the working portions of said paths of movement, and means for Imoving said folder units around said paths with the -second unit traveling at a faster rate and with a differential such that the second unit will pass over the rst unit as ythe units pass from the point `of divergence to the working portions of said paths.

2. In a wrapping machine, a plurality of first and second folder units, a rst pair of endless chains to which opposite ends of said first units are secured in longitudinally spaced relation, a second pair of endless chains to which opposite ends of said second units are secured in longitudinally spaced relation, the number of said second units being greater than the number of said first units, -said chains having upper, parallel, operative runs and divergent r-uns, first and second pairs of sprockets at each end of said parallel runs and said first and second pairs of chains being respectively trained about said sprockets, a first shaft mounting the sprockets at the infeed end of said parallel runs and a second shaft mounting the sprockets at the discharge end of said runs, said second sprockets having a greater diameter than said rst sprockets, and means for driving said shafts and sprockets and moving both pair of :chains in the same direction along said parallel runs, said second pair of chains moving at a faster rate, the paths of travel of said folder units being coextensive along said parallel runs, said first and second units being alternately spaced apart along said parallel runs with each second unit being spaced from the next preceding first unit at the beginning of said coexteusive paths of travel sufficient to prevent colliding with said next iirst unit as it approaches same along said coextensive paths, each of said second units passing over the next succeeding first unit as they are carried along the divergent runs of said chains.

3. Apparatus as in claim 2 wherein the wrapping machine comprises a first platform adjacent the infeed end of said parallel runs and at the same level as the coextensive paths of said folder units, and means for draping a wrapper about an article with the leading end portion of the wrapper underlying the article and with the trailing end portion trailing therebehind, and further wherein means are provided for advancing the articles from said platform to said folder units with the article traveling at the same rate as said first folder units and in register with one of said folder units, said trailing wrapper portion being permitted to fall between the named first folder unit and the next suceeding second folder unit, and further wherein a second platform is provided at the discharge end of said parallel runs and said second platform also being at the same level assaid coextensive paths and the first folder unit is provided with means for drawing the leading wrapper portion away from the bottom face of the article to permit the trailing wrapper portion to be folded against the bottom of the article, the article advancing means then advancing the article onto said second platform to thereby lay the leading wrapper portion against the bottom face of he article in overlapped relation to the trailing wrapper portion.

4. Apparatus as in claim 3 wherein the first and second pairs of chains are respectively trained about first and second pairs of sprockets at each end of said parallel runs, the sprockets at the infeed end of said runs being mounted on a first shaft, the sprockets at the discharge end of said run being secured to a second shaft, said second pairs of sprockets having a greater diameter than said first pairs of sprockets and means for rotating said second shaft at a given rate to obtain a greater linear rate of travel for said second folder units and further wherein means are provided for training said second pair of chains outwardly of said first pair of chains as the chains pass along their lower runs from said second shaft to said first shaft.

5. Apparatus as in claim 4 wherein each first folder unit comprises a mounting bar secured at its opposite ends to said first pair of chains, a suction bar pivotally n connectedto said mounting bar about an axis transverse to the direction of movement of said chains and underlying the terminal end portion of said wrapper when the iirst folder unit is so registered, each second folder unit comprises a folder bar having its opposite end portions raised and connected to said second pair of chains and means for pivoting said suction bar away from said article as the folder units approach saidsecond platform.

6, Apparatus as in claim 5 wherein the means for pivoting the suction bar comprise spring means urging the suction bar away from the article and a cam track maintaining said suction bar at the level of said first and second platforms at the infeed end of said coextensive paths and then permitting the suction bar to swing away from the article upon approaching said second plaform.

7. Apparatus as in claim 6 wherein each first folder unit further comprises a U-shaped bar secured at its opposite ends to said first pair of chains and providing an anchor for said spring means pivoting the suction bar.

8. Apparatus as in claim 7 wherein the folder bar of each second unit overlies the U-shaped bar of the next succeeding folder unit.

References Cited bythe Examiner UNITED STATES PATENTS 10 FRANK E. BAILEY, Primary Examiner. 

1. IN A WRAPPING MACHINE, FIRST AND SECOND FOLDER UNITS, A PLATFORM, SAID FOLDER UNITS BEING MOVABLE AROUND CLOSED PATHS, SAID PATHS HAVING COEXTENSIVE WORKING PORTIONS EXTENDING TOWARDS SAID PLATFORM, SAID PATHS THEN FALLING BENEATH SAID PLATFORM TO A POINT OF DIVERGENCE, THE PATH OF SAID SECOND UNIT FROM SAID POINT OF DIVERGENCE BACK TO SAID WORK PORTIONS BEING GREATER THAN THE LENGTH OF THE PATH OF SAID FIRST UNIT BETWEEN THESE POINTS, SAID FIRST UNIT BEING SPACED A SUBSTANTIAL DISTANCE FROM SAID SECOND FOLDER UNIT AT THE BEGINNING OF THE WORKING PORTIONS OF SAID PATHS OF MOVEMENT, AND MEANS FOR MOVING SAID FOLDER UNITS AROUND SAID PATHS WITH THE SECOND UNIT TRAVELING AT A FASTER RATE AND WITH A DIFFERENTIAL SUCH THAT THE SECOND UNIT WILL PASS OVER THE FIRST UNIT AS THE UNITS PASS FROM THE POINT OF DIVERGENCE TO THE WORKING PORTIONS OF SAID PATHS. 